This invention relates to a cylinder lock manufacturing method in which a plurality of cylinder locks that are used in different places but can be unlocked by a common key such as the various locks in an automobile are manufactured as a set of locks complete with a common key.
Cylinder locks used in an automobile include a steering column lock, door cylinder locks for both the left- and right-side doors, and a trunk lock, etc., all of which have the same key number and use a common key for their unlocking.
To manufacture a plurality of such cylinder locks having the same key number and using a common key but used in different places, as shown in FIG. 3, inner members thereof obtained through an inner member casting process a have tumblers assembled into them by an automatic tumbler assembling machine and thereafter are conveyed to respective assembly lines such as a steering column lock assembly line c, a right-side door lock assembly line d, a left-side door lock assembly line e, and a trunk lock assembly line f so as to be assembled therealong as the respective locks. In the steering column lock assembly line c during this assembly process, the steering column lock being assembled is further combined with a key manufactured through a key-notch working process g and stored in a storing box h. The steering column lock now complete with the key is conveyed to a set line i, whereas in the other assembly lines, the cylinder locks are assembled without a key and moved to a stock yard j where they are lined up in order of key code number in each packet for each assembly line and kept for temporary storage. After their key code numbers are compared with that of the steering column lock with key which is moving along the set line i, they are transferred to the set line i to be grouped with the corresponding steering column lock with key which is moving along the set line i, they are transferred to the set line i to be grouped with the corresponding steering column lock with key and packed together therewith as a group of cylinder locks .using a common key for unlocking thereof.
In such a conventional method as described in the foregoing, it is not only complicated and troublesome to keep a stock of the cylinder locks stored temporarily in the stock yard j under control, but also impossible to group and pack them together in a set unless all the assembly lines are synchronized with one another. Furthermore, this process of grouping together the cylinder lock complete with the key and the other corresponding locks without it is carried out in a sort of card-pairing manner such that each of the respective locks from the respective packets in the stock yard of each line has to be compared individually with the lock complete with the key. This makes the grouping process quite troublesome and inconvenient.
The present invention whose objective is to solve such problems as noted above provides a cylinder lock manufacturing method wherein a plurality of cylinder locks using a common key for their unlocking but used in different places are taken as a group having a specific key code assigned thereto. The cylinder assembly process in which inner members and outer members of cylinder locks are assembled into respective cylinder locks is carried out continuously for one group after another with change of the key code. The key notch working process in which a key for each group of the locks is notched is carried out synchronously with the cylinder assembly process. The cylinder locks and the key so produced through these processes are then combined as a set.